Tank closure



J, NELSON ET AL TANK CLOSURE Filed Jan. 28, 1953 .lune 18, 1935.

"""liflllllulllll 2 Sheets-Sheet l INVENTORS .Q0 (/0/7/7/1/6/50/7 ATTOR Y June 182 1935. J, NELSQN p -r AL 2,005,469

TANK CLOSURE Filed Jan. 28, 1935 2 Sheets-Sheet 2 ATTORNEY Patented June 1s, 1935 2,005,469

UNITED STATES PATENT oEElcE TANK CLOSURE John Nelson, Minneapolis, Minn., and. Victor C.

Norquist, Kansas City, Mo., assignors to Butler i Manufacturing Company, Kansas City,v Mo., a corporation of Missouri Application January as, 1933, serial Nc. 654,006

claims. (ci. 22e-44) Our invention relates to tank closures and more Fig. 4 is a sectional View taken on the line d-ll, particularly to a closure provided with a re- Fig. 2. proof vent, for tanks adapted to contain and In general, our invention contemplates a large transport inilamrnable liquids. opening leading to the interior ofthe tank and 5 In transporting or storing inflammable liquids, separated therefrom by means of a plurality of 5 it frequently happens that the lighter ends of a foraminous screens. Inboard of the screens and liquid will volatilize to form explosive or inflamblocking an opening leading to the interior of the mable vapors. This vapor will escape from the tank, we provide our novel valve arrangement. tank due to the expansion occasioned by the heat The valve arrangement consists of a series of l0 0f the Sun, 0r by the displacement of the vapor three valves. A large valve is adapted to lift to l0 due to the lling of the tank. expose the maximum opening of the tank. This It is knownv in the art to provide fire-proof Opening Will be SUnCenlY large t0 Vent the tank screens to vent a tank to allow the escape .of the in event the tank car or receptacle be subjected vapors without the danger of fire. It frequently t0 the heat 0f a re. Within the large valve We happens, however, that a re adjacent the tank, provide two valves, one adapted to lift in event i. or an extremely hot sun will cause such a rapid the pressure within the tank be decreased by a volatilization of the liquid that the vapors will I'edllC'fiOn 0f the temperature 01 by withdrawing not escape rapidly enough. This is particularly liquid from the tank to relieve the partial vacuum true also when the tank is being lled. In other Which Would be 1711115 formed. We -DI'OVde OO 2O words, the venting requirements necessary for a another valveadapted to lift in event pressure 20 tank will vary depending upon certain factors. be created due t0 the expansion 0f the vapors Normally, a small vent, will suce for al1 praeand/or liquid within the tank due to an increase tical purposes, Occasions may arise Where a in the temperature and/or the lling of the tank. larger vent will be needed, More particularly, referring now to the draw- One object of our invention is to provide a tank ings, a C10S1l1`e member i iS SeCUled t0 a large closure which will adapt itself to all venting re- Opening Within the tank by lVeting, Welding 01 quirements and at the same time be perfectly safe 111 any other Suitable 11131111612 The ClOSU-Ie memwith respect, to the me hazard ber is provided with an opening 2 which may be Another object of our invention is to provide used as a filling 01 gauging Opening The ClOSllre a tank vent which Wm allow for both expansion member is also provided with a larger opening 3 and contraction of the liquid and/or vapor withdefined by e COemng 3- The IOWeF DOTOn 0f the in the tank, Whe maintaining fire proof con.. coaming terminates in a flange fi and supports a dimens plurality of screens 5. These screensfmay be of A further Object of our invention is to provide foraminous sheet material or of metal mesh. A a novel closure which will prevent the explosion plurality 0f pillars 01 DOSS are Supported, by 35 of a tank in event of an adjacent fire by permit- Phe aange and Support a @over Plate 7 The ting the' rapid Venting of the volatilized liquid interior per1phery of the flange t is rovided with.

A Stm further object of our invention is to a packing ring which forms .the valve seat for provide a vent which will preclude the stress oca' large Valve 9- The Valve 9 1S Provided With e Casioned by temperature Changes and the resu1t central bore l0 wh1ch communicates with a pair 40 ing expansion and contraction of the gas and/or of bores H and 2 runnmg at nght angles t0 the liquid Within the tank bore i0.. The bores It and I2 are in communica- Further objects of our invention will appear non Wlth th? atmosphere through th? Screens from the following description 5. The interior of the bore l0 1s provided with In the accompanying drawings which form a T a'bbet .3 in .which is Seated a packing ring M' 45 part of the instant specification, and which are Thls packmg Img M forms a' Seat for a.va1ve d5 to be read in conjunction therewith and in which as can readlly be Seen by reference to Figs 2 and 4. The valve I5 is provided with a valve stem H6 /lesnumemls refer to hke parts m the which is slidably positioned in a valve stem guide il. The upper portion of the valve 9 is ro ide F1g- 1 15 a' plajn Vlevf 0f our Closure agssembl with a bore i8. This bore I8 is proviedvwitl 'F1a-2 1S a Seeilonel VleW teken 011 the 11n@ 2 2, a rabbet is in which is seated a packing ring zc.

Fig. 1. This packing ring forms the seat for a valve 2 I. Fig. 3 1s a sect1onal view taken on the line 3 3, The bore I8 is covered by a cover plate 22 which 55 Fig, 2. is held in place by screws 23, thus making it inte- 55 gral with the valve 9. The interior of the cover plate 22 is provided with a socket 24 which acts as a guide for the valve stem 25 of the valve 2l. The space in bore I8 above valve 2I is in communication with the interior or the tank by means of a pair of ducts or bores 26 and 21, as may readily be seen by reference to Fig. 2. Bore I8 communicates with an enlarged space 28 in which valve I5 is seated and into which bores or ducts I I and I2 lead. The valve 9 is provided with a handle 29 so that the entire assemblymay be lifted from the valve seat 8 after cover plate I is removed by removing nuts 30. This will give access to the interior of the tank for men when it is desired to inspect or clean the same. The entire assembly is protected by a hinged cover plate 3l which is pivoted to lugs 32 secured to closure member I, as can readily be seen by reference to Figs. l, 2 and 3. Pin 33 forms the pivot for the cover plate 3|, which is provided with a lug 34. The lug 34 has an opening 35. The small opening 2 which may be used for a illling or gauging opening, is provided with a cover plate 36 hinged to the closure I by means of pin 31. The small cover plate 36 is provided with a hasp 38 which may be secured thereto in any suitable manner. The hasp 33 is adapted to nt over lug 34 so that a lock may be placed through opening 35 to secure both cover plate 3i and cover plate 36.

In operation, when the tank is being illed at a slow rate, or if pressure accumulates within the tank due to expansion, valve I5 will lift and the pressure released through ducts II and .I2, through the screens 5 to the atmosphere. If the `tank should be adjacent a re or if it is being filled at an extremely rapid rate so that valve I5 is insuilicient to take care of the accumulated pressure, large valve 9 will lift and vent the pressure to the atmosphere through screens 5. 1f a light vacuum should be built up due to contraction of the gases and air within the tank, this vacuum will communicate with bores 26 and 2'I to the top of valve 2|, which will lift and permit the reduced pressure to be equalized by the passage of air from the atmosphere through screens 5, through ducts II and I2 to the space 28 above valve I5 and into the tank. It will be observed that the passage of vapors out of the tank or of air into the tank is always through screens 5, so ,that there is no danger of re.

It will be appreciated that we have accomplished the objects of our invention. We have provided'a novel tank` closure which will vent under different venting requirements from the slightest to the most severe. Our tank closure renders a tank practically immune from re or explosion due to the fact that any sudden or large increase in pressure may be vented by means of the large valve 9. The valves 2| and I5 will take care of the usual variations in pressure due to expansion and contraction and/or the filling or withdrawal of liquid from the'tank.

-sub-combinations. Thisl is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is,`

therefore, to be understood that our invention is not to be limited to the specific details shown and described. x

Special attention is invited to valves I5 and 9. Valve I5 is somewhat lighter per unit of area than is valve 9. It will be noted that this will permit valve I5 to operate iirst to take care of all normal expansion in the tank, while valve 9 will only operate when the expansion is abnormal or too rapid to be taken care of by valve I5, which, being heavier per unit of area, will remain stationary while valve I5 operates.

Having thus described our invention, what we claim is:

l. A closure for a tank comprising a plate having an opening, a rst valve seated in said opening, said first valve being provided with two ducts connecting the tank inside with the atmosphere, a second valve seated in said first valve and controlling one of said ducts, and a third valve seated in saidv rst valve and controlling the other of said ducts.

2. A closure for a tank comprising a plate having an opening, a valve having two bores seated in said opening and adapted to lift to release pressure within the tank, an auxiliary valve seated in one of said bores in the valve adapted to lift to release pressure within the tank, and a supplementary valve seated in the other of said bores in the valve adaptedto lift to release a partial vacuum within the tank.

3. A closure for a tank having an opening including in` combination a rst valve seated to close said opening, said valve being formed with two ducts providing communication between the tank interior and the atmosphere, a second valve seated in said rst valve and controlling one of said ducts, and a third valve seated in said first valve and controlling the other of said ducts.

4. A closure assembly for a tank opening including in combination a valve formed with two passages and a, pair of auxiliary valves controlling said passages, the construction being such that the assembly is adaptedv to lift to release pressure in the tank, one of said auxiliary valves is adapted to relieve pressure in said tank and the other of said auxiliary valves is adapted to release a partial vacuum in the tank.

5. A closure as in claim 3 wherein foraminous material is disposed adjacent the rst valve to extend across the communication between the tank interior and the atmosphere.

JOHN NELSON. VICTOR C. NORQUIST. 

